The present invention relates to skylights, and more particularly to such skylights including separate curbs and domes with a seal interposed therebetween.
Skylights are becoming increasingly popular in both commercial and residential construction. Skylights greatly enhance the illumination, and apparent roominess, of a building interior by admitting natural light and providing a psychological feeling of openness not possible with wallmounted windows.
In response to different building needs and different budgets, many different skylight constructions have been developed. One particularly popular type of skylight includes a curb, a dome, a seal interposed between the curb and dome, and a retainer for securing the dome in position on the curb. The curb is a mounting structure supported by the structural roof. The seal is mounted on an upper portion of the curb to support and seal the dome thereagainst. The skylight rests directly on the seal and compresses the seal to form a weather-tight seal between the curb and dome. The retainer fits about the peripheral edge of the dome and is secured to the curb to maintain the dome in position against the curb and draw the dome against the seal.
A wide variety of materials has been developed for use as the seal between the curb and dome. Known materials used to date include neoprene rubber (see U.S. Pat. No. 2,947,267 to Stark and U.S. Pat. No. 4,193,237 to Jankowski), cork and/or plastic (see U.S. Pat. No. 2,968,263 to Huston et al), felt (see U.S. Pat. No. 3,090,613 to Bechtold), foams (see U.S. Pat. Nos. 3,350,823 to Murray, 3,555,752 to Bogaert, and 4,223,493 to Moench et al), butyl tape (see U.S. Pat. No. 4,073,097 to Jentoft et al), and butyl glazing compound. However, all of these materials are not without their drawbacks. For example, the butyl glazing compound (known as a "wet seal") remains soft and tacky throughout its life and adheres to any contacting surface. Consequently, replacement of a dome during installation or subsequent servicing is complicated since the butyl compound must be removed from both the curb and the dome after the skylight is removed and a new butyl seal applied. This is time-consuming in terms of labor and consequently cost. The self-adhesive butyl tape (known as a "dry seal") is relatively thin and therefore requires carefully controlled manufacturing tolerances in the mating surfaces providing contact area with the relatively thin tape. The remaining gasket materials do not adhere to either the curb or skylight. Accordingly, these seals require additional structure to hold them in place. Further, many of these seals have been found to be undesirable for reasons of cost, increased brittleness over time, or inadequate weather sealing.
As a recent development, Wasco Products, Inc. of Sanford, Me. has developed a plastic curb with a coextruded seal having a durometer lower than the curb body (see U.S. Pat. Nos 4,589,238 to Sampson et al; 4,527,368 to Jentoft; and 4,570,394; 4,449,340; and 4,409,767 to Jentoft et al). However, the coextrusions are relatively expensive increasing the resultant cost of the skylight.
Other seals have been developed for different applications in different products. For example, ODL, Incorporated of Zeeland, Mich., the assignee of the present application, has applied a foamable gasket to the exterior frame of a door light to provide an integral weather seal between the frame and the exterior surface of a door in which the light is mounted. The applied gasket is dry to the touch, self-adheres to the frame upon application, and is resiliently compressible. The gasket is positioned to be compressed by the door; and the frame with the integral gasket is therefore ready for installation without the installer having to apply separate glazing.